Telephone system



March 22, 1932. R. L. QUASS TELEPHONE SYSTEM 1 #mtmm; S H RS t I met 93k0 m MN A k w a ow mat mat [b IE 1 IL March 22, 1932. R. L. QuAssTELEPHONE SYSTEM Filed July 31, 1930 5 Sheets-Sheet 2 v n vokmmx NON\ERNQQ m Ewfi V 263 .BN

i i M llllllllllllfiu P u i4 INVENTOR R. L; QUASS A 7' TORNEY March 22,1932. R. QUASS TELEPHONE SYSTEM Filed July 51, 1930 5 Sheets-Sheet 5INVENTOR R. L'. Q UASS ATTORNEY March 22, 1932. R. L. QUASS TELEPHONESYSTEM Filed Ju ly 31, 195,

5 Sheets-Sheet 4 QM k In H n QESQQEQ I-II Ill-I INVENTOP R. L.QU/4 55 A7' TORNEV Filed July 31., 1930 5 sheets sheef 5 E 3x26 Q Q QNQ nws/vroR. L. QUA s s ATTOPN V whereby other circuit changes are eil'ccted bythe operation of said trip relay to supply battery feed conditions insaid preceding switch for the talking conductors.

Another feature consists of means whereby when the connection isextended to certain types of trunks or to operators positions, boosterbattery is applied to the tip conductor and the battery connection ismaintained'on the ring conductor to cause both said test relays toremain operated and in addition to cause a third marginal test relay tobe operated over the tip conductor circuit to prevent a signaling codeto be transmitted and to complete the connection through the precedingswitch without supplying transmission battery'for the talkingconductors.

) This invention hasbeen illustrated in the accompanying drawingsin'which:

Fi 1 shows a calling subscribers lines, a I line der in diagrammaticform and a first selector switch embodying features of this invention; 1Fig. 2 shows an intermediate selector I Fig. 3 shows-a connectorembodying other features of this invention;

1 access to trunks leading to a distant office and maybe used in placeof Figs. 3 and' l in connection with Figs. 1' and 2; and

Fig. 6 shows a trunk circuit outgoing from one oflice, a trunkterminating in a connector at a distant ofiice which connector maybeused'for extending calls through standard automatic step-by-stepswitches to called sub-- scriberslines one of which has been shown indiagrammatic form.

Fig. 7 shows how the above figures may be arranged for reading of thecircuits thereon.

Referring to the drawings, a description will first be made of a callfrom the calling subscribers line at 1 through the line finder LF, thefirst selector S, the second selector S and the connector C to asubscriber of the four-partyline 300. A description will then be made ofa connection extending through a connector similar to connector C butwired in accordance with Fig. 4 to another subscriber of the line 300. Adescription will then be made of a connection from the callingsubscriber at 1 over line finder LF, selectors S andS'and the trunkhunting connection C1 of Fig. to an idle trunk outgoing to a distentofiice and finally a description will be made of a connection from thesubscriber 1 over line finder LF, selector S, the trunk cirjcuitT andtrunk Tlto a distant oflice to a selector S2 and then through suitableswitches (not shown) to a called subscribers matic form in thesedrawings may be of any well known ste -by-ste t When the, sgbscribei' at f has established in the usual manner a connection through linefinder'LF to the selector S a circuit is established for the operationof relay 10 as follows: Batter winding of relay 10, inner lower make-beore-break contacts of relay 11, inner lower'make-before-break contactsof rela' 12 to the ring conductor over the line fin er LF and thesubscribers loop back through the line finder over the tip conductor,

, the upper make-before-break contacts of relay 12, the outer uppermake-before-break contacts of relay 11 to ground. 'Rela 10 in operatingcloses an obvious circuit or the operation of relay 13 which is slow inreleasing and remains operated during the operation and release ofpulsing relay 10 in response i to the digits. Relay 13 is held operatedwhile relay 10 is released by a locking circuit closed through thesecond lower armature and front contacts of relay 14. which is operatedduring the sending of the impulses of each digit as 'will hereinafter bedescribed. ()n the operation of relay 10 the condenser 15, which isnormally eharged'from battery throu h the lower winding of relay 16,disc arges through resistance 17 to ground. On the first release ofrelay 10 in response to the first impulse a circuit is completed frombattery, winding of rela. 16, upper armature and back contacts 0 relay10, condenser 15 to ground. This circuit charges condenser 15 and thecurrent produced thereby through the lower winding of relay 16 causesthis relay to operate. 7 Relay 16 in operatin closes a locking circuitfor itself from battery through its upper winding and upper innerarmature 'and' front contact, upper inner armature and back contacts .ofrelay 18, rotary ofi-normal contacts 20, vertical ofi-normal contacts21, conductor 23, upper'outer and armature and back contacts of relay11, second upper armature and back contacts of relay 12, second lowerarmature and back contacts of relay 24, lower inner armature and frontcontacts of relay 13 to ground. On the operation of relay 16 an obviouscircuit is closed for the o eration of relay 14 which is slow inreleasing and remains operated during the sending of the impulses ofeach digit. Relay 14 in operating closes the above mentioned lockingcircuit for relay 13 and also a circuit as follows: Battery, lowerwinding of relay 12, winding ofrelay 25, lower inner armature and frontcontacts of relay 14, winding of rela 26 to ground over conductor 23 ashereinbe one de scribed. This circuit causes relays 25 and 26 to operatein series while relay 12 remains deenergized as relay 12 is of amarginal character. The vertical magnet 27 is also 0 rated on theoperation of relay 16 from bittery, winding of yerticah magnet 27, lowerinner} armature and back contacts ofirelay 18, lower armature and frontcontacts of relay 16 to ground on conductor 23. The

operation of the vertical magnet 27 causes the brushes ofthe selectorto" advance one step.- 7 In this movement of the selector, the

vertical oft-normal contacts ,21 are shifted to switchrthe lockingcircuit for relay 16 to ex ;tend ;through the'lower'winding off-relay28" to'jgr'oundat'the armature and back contact ofma'gnet27. However inshiftingthe ver- "ticalofi' normal contacts 21 the hold-ing'cir chit-forrelay16 is opened and relay 16 re 4 1'5 is'discharged and on the nextrelease of relaylltl, relay 16-is again operated causing the operationof the magnet. -27.- The locking circuit for relay Iii-is now extendedas hereinheforementioned to the ground at the armature of inagnet27, andthis lochingcin cuitis opened onthe operation of magnet 27, causingrelay'16-to release. Relay 16 is tlierefore heldoperatedeach time undercontrollof magnet 27*afterl1aving been mo'nientarily energizedZhy therelease ofrelay 10.

7 These,- operationsofrelays 10' and 1'6'and of r 'inagnet27 continueuntilallthe impulses of "the-firstfdigit have heensent to advance thehrush esfot switch Sto the desired level.

Belay 28 is marginalso that itwill not opope'rate in the locking.circuit for relay 16 due-to tl e high,1iesistance ofthe upper windingfotrelay 16L ,At. theend (it this series ot iropulses, relay 1 1releasesand' this causes a circuit to be completed forthe operationojrelay28 as follows 2 Battery,lower.windingot relayl 2, winding ofrelay 25, lower fouter armature 'aindjhack contacts" ofrelay 1 1, upperinnerarmature and back contacts of relayj16, upper innerarmature andback contactsofrelay 18, rotaryoifnormal contacts '20, ertical; oif norna-l contacts 7 21, upper winding of "relay; 28. to ground at thearmature1 an d backcontactsofn agnet 27. Relay 25fisinaintainedoperatedinthis circuit while 'relayf12 remains released andgrelay 26 releases.The release offrelay26, however, has no effect on the circuits atthis-time.

yious circuit for the rotary magnet 30. The

energizing circuit-for relay 28 is now opened due' to the shiftingoftherotary ofi-normal contactsj20 and relay 28 in releasing causesreleaseofjmagiiet i) the brushes of the selector now contact withthe.terminals of thefirst trunk leadingto a second selector. Ifgthisselector is busy there willbe a ground on thesleeve terminal and thisground cause a circuittto be closedfor the reoperation of:

relay 28 from battery, lower winding of re "lay; 28, armature andbackcontacts of mag-- net- 30; rotary oii normal contacts 31, lowerouter armature and back contacts #of relay leases fTliis causestherelease ofmagnet2'7. 5 Onthe next-operationof relay 10, condenser Theoperation oirelay 28 closes an 010- 18, lower outer. inalre-before-breakcontacts of relay: ll, lower. outer make-before-hreak contacts of'relay.12 to'ground on the sleeve terminal of thesbusy second selector. T1116operationof relay 28 wagaincloses the circuit for the magnet-'30t-oadvancefthe brushes to the terminals ofcthe. next second selector:mag'net-SO opensxthe circuit forrelay'28et its armature and backcont'actg-and relay-28 releases..- The alternatefoperation and re lease-oi .magnet '30 andrelay .28 will now continneuntil an idle secondselector: has been found. I When this takes place, theablay 28,armature, andloack. contactofmagnet 30, winding of relay ,18:to thegroundon conductor 23." The lower windingof; relay 28 is also marginalin character so thahthis relay willnot operatein thecircuit fortheoperation of. relay18. Relay 181opensthe pulsing circuit ior" magnetv27,,at its lower nnerarmature and hackcontact and extends the pulsingcircuit over the, ring conductor" to the secondzselectorSl' atthls-armatureand'its front. contact, the lower inner armature and backcontact otrelayll, lowerinneriarmatureaiidhack contact otrelay 12,

ring. conductor of selector S1, upper inner armature and back contact-ofrelay 201,

windingiof the vertical magnet 202to bat tery. Relay 18 also extends thelocking circuit for relayj 16 through its inner upper. and front.contact, third u'pper armature and j back. contact of relay 11, thirdupperlarmature and back contact offrelay 12, tip conductor of selectorS1, upper outer-armature and rback. con-tact of relay 201, rotary ofi'--normal contacts .203, vertical off-normal contacts 204 to ground. Thesecond-selector S1 sence of ground on the sleeve terminal willthen'causethe operatlonot relay l'81overi a" circuit irom battery, lowerWinding of rjes is nowin conditionfor receptionof the im- 7 pulse :ofthe second digit.

'The operation of relay 18 also placesqa busy. groundbon the sleeveofselector- S1 from ground at thev inner low armature; and

making the selector S1 busy. c 7 Th s ground on the sleeve isnow'connected through thef armature and hack contacts of release'inagnet.2 05',f'second lower armature I and back icontact'of relay 201,upperwinding'ot relay- 2O1 to battery. This circuit causes the partialoperation of relay 201i'to open. the connection to ground through itslower outer armature and'front contactto prevent the operation oftherelease 'ma'gnet 205 atthetiine the vertical magnet 202 operjates toshift the vertical 1 ofi n rmal contacts 206 on the subsequentoperationt of:theslvertical magnett202i in: response-toathe second"- iand a circuit will then be completed for the series of impulses. \Vhenrelay 16 responds to the first impulse of the second digit, verticalmagnet 202 operates over the circuit throu h the ring conductor ashereinbefore 5 descri ed and the locking circuit for relay through thevertical off-normal contacts 204.

through the upper winding of relay 207 to round atvthe armature and backcontacts of the vertical magnet 202. From this time on this lockingcircuit is controlled by magnet 202. Relay 207 is marginal in characterand will not be operated by this circuit through its upper winding.

When the second series of impulses ceases "relay14 releases ashcreinbefore described operation of relay 207 over the circuithereinbefore described extending from battery, windings of relays 12 andand contacts of relays 14, 16, 18, 11 and 12 over the tip conductor. Therelay 26 is in this case maintained operated due to the operation ofrelay 18 over the circuit from battery through the winding of magnet 202and contacts of relays 201, 12, 11, 18 and the inner lower armature andback contact of relay 14 winding of relay 26 to ground on conductor 23.The rotary magnet 208 is now operated over an obvious circuit due'to theoperation of relay 207 to advance the brushes of the selector S1 to theterminals of the first connector. If this connector is busy a groundwill be present on the sleeve toclose a circuit for the reoperation ofrelay 207 which is released on the first step of rotary magnet due tothe shifting of the rotary oil-normal contacts 203. The ground for thetip conductor is now supplied through the shifting of the rotary oil"- Inormal contacts 203 to maintain relay 25 operated; The'circuit for relay207 may be traced from battery through the lower wind- -ing of relay207, rotary off-normal contacts 209, lower inner armature and backcontact of relay 201, sleeve conductor to the ground on the sleeve ofthe connector C. Relay 207 in operating closesthe circuit for the magnet208 and this magnet in turn opens the circuit for relay '207.' Thesealternate operations of relay 207 and magnet- 208 are continued until anidle connector is found, when relay 207 will be permanently released anda circuit completed for the full operation of relay 201 1 as follows:Battery, lower winding of relay 207, rotary elf-normal 1 contact 209,lower lower innerarmature and front contact to the the vertical magnet304 to winding of relay 201, lower armature andv sleeve of the connectorC to make it busy.

Relay 201 also extends the tip and ring con- 7 ductors from selector S,through selector S1 to the connector C and the circuits'are now, incondition for the reception of the last two series of impulses tocontrol the connectorU.

To select the desired subscribers line the connector C may be operatedto select either oneof two sets of terminals leading to the desiredline. ,In one case the tip and ring conductors are connected as shown inFi 3 and in the other case the tip and ring con uctors, are reversed.The ringing will take place on, the ring conductor and the bells of thesubscribers on this lineare connected as shown at 300, that is, thebells of two subscribers connected to one conductor and the bells of theother two subscribers connected to the other conductors. To distinguishbetween the two bells on one conductor the ringing will be a pliedincodes of oneor two impulses and it will be explained hereinafter how thecode signals are selected.

Returning now to the transmission of the last two digits to select adesired subscribers line, the ground connection for the ti conductor tomaintain rela 25 operated and to lock relay 16 as hereinbe ore describedwill now be supplied on the operation of relay .201 from the ground atthe vertical off-normal contacts 303 through armature and back contactof the vertical magnet 304, armature and back contact of the rotarymagnet 305 up r outer armature and back contact oi re ay 307, upperouter armature and back contact .of relay 309 tothe tip conductor to thesecond selector S1 through the upper outer armature and front contact ofrela 201 to the tip conductor to selector S, w ile the pulsing circuitwill be extended tov the vertical magnet 304 through the inner upperarmature. and front contacts of relay 201 over the ring conductor to theconnector and the lower inner armature and back contact of relay 309,second lower armature and back contact of relay 307, thirdlower armatureand front contact of rela 310, winding of batter It should be obviousthat the connection rom ground at the selector S through the sleeveconductor of selector S1 and connector C is extended through thearmature and back contact of the release magnet 312, the verticalofi-normal contacts 313, lower winding of relay 310 to battery. Thiscircuit causes the partial operation of relay 310 to open the connectionthrough its outer lower armature and back contact for the rotary magnet305 and extend itthrough this armature and the associated front contactto the winding of the vertical magnet 304, so that the above mentionedcircuit for the vertical magnet 304 will be completed as described. Thisground connection from the sleeve will also be extended through thearmature and back contact of release magnew: a

307 torbattery to pantiallyoperate relay 307 to open the connectorthrough 'its lower outer: armatnreand back Contact tofprevent the operation of the release "magnetwhen the ofinormal contacts 325farefclosed; f Allocking' circuit fornuaihtainingrelay 310 :in' partialI gcircuitftlirough thei'ringconductor and the v I windingo'f the.rotary'magnet 305. In case operation, will also 'be closed from batterythrough the flower winding of this relay, thellorwer outer varmature;and 'back contacts otrelay, ,314 (to ground on ,the, third lowerarmature and back; contactiof relay i309. 3:011 I the first pulse I ofthe next digitflthe yertic-al magnet .304 will operatee oyer theabovemene tioned plilsing cirouit and the locking circuit forilrelay ,16,will be I opened not ,1 only at the armature .an'd backicontact of thevertical magnet 304Ibut also at the @Vertical ofl'enornia'l contacts303, which icontacts shift the ground vconnection for this; lockingcircuit to ground throughthewinding or relay 314,

This'flocking circuit is necessary asthe vertical ofi-norinalcontacts313 open on the-first step of the; vertical magnet the original energizig circuit ,forrre'lay impulse of this digit, the locking circuit fforrelay 16willbe opened at the armature and back contactslo'f the vertical,Inagnet 304. Belay 314whih5-is marginalfin characterwill not "operatethrough this locking circuit during the;sending. ofthe-oimpulse'sl Whenthese impulses cease,"how,ever,andlrelay16,1eleaseS; relay 14 releasesits hereinbefore "described and a circuit ,}will' be extended frombattery thronghtthe windingorelay212eand winding of relay 25,, lowerarmature and'hack contacts o'frelay '14 andjthetip conductor as hereinbeforedescribed, toiqground through the winding of relay f3l4causingthis relay to operate. This relaylinoperating opens the, locking circuitfor relay310 which nowrei "leases and transfers the pulsing circuitthrough its lower outer armature and'back contact to battery through:the winding of rotary magnet 305. The rotary; magnet 305 1 does. notoperate through this circuit; hereinbefore traced to'ground overconductor 23 through the winding ofrelay' 26 and contacts of relays-14'and 318 over the ring conductor,

' i but maintains relay 26' operated until the next series of impulsesare-transnii tted.

Thenextseriesof'irnp'ulses of the'lastfdigit will now operate magnet304Ltoadvance the brushes of connector C until they areassociatedwitli'the terininals of the desired subv scribers line "300.The locking'circuitafor relay '16 as hereinbefoiie described, is eixtending through the winding of the marginal relay 314duringthe sendingof the impulse for this digit and relay 1314 will therefore againreleasefduring the sending of this series of impulses. Relays 25 and 26will be main- "tained operated 'd'uring'thesending of these impulses inthe series connectionestablished by the operation of relay 14; WVhenthis se- 3 o the calling subscrlib fl a i 310. ,At' the next I ries ,ofirnpulseslare ceinpleted and on the the windingsof relays25fa nd 12 tomain-' tain relay 25 operated. Relay314 will therefore now be operated a"second time, "while; h

relay 25 willlbema'intained operated in the the desired subscriberslineis'busy relays 314 and 307 operate as usual but relay 310 does notoperate as a ground is present a on the Y sleeye o" f the busy line.Hence when relay309,

operates a busy signal from the sourcef330 and; ground 33Iareapplie'cl'over the second and tliird upper ai'matures andfront contacts of relay"307, upper armatures and back contacts of relay-i310 and upper andinner lower armaturesand front contacts of relay 7 The circuitsarenowprepared forithe sending'o'f the proper ringing code to signal thedesired subscriber. The selection bythefse lector S1 willdeterminethecodeto beftrans y inittedhy selecting ani'idle connector from 7 eitheroneof two groups of connectors. This selection .fwillfbrin'g aboutvcircuit operations i thge selector S1110 apply the oneringcode'orthetwo ringv code. If the one ring c'ode is de- I the selector S1 willselect an idle con; nector wired a's co'nnector'C and particularly asshown at the arminalserz while if a two ringoode isdesired'the-selectorSlwill select a connector wired'the same as iconnectorC except esshown, at '318'of13ig. '4.

Assunnng that the; connector Chas been 3 selected withithe connectionsas shown at31'7 the following operations 'willnottakeplace to extend the"connection: to the line 1300 and applythe one ring coile atfthecompletion of theseries ofimpulses o'frthe last digit. As

shownrelay 307 will be operated over a cir-' f cuitirombattery'throughthe 'lowe'rwinding 'ofithisrelay; the rotary ofit normalcontacts i' I39.0,"lower' inner armature and, front contact of relay 3l4 to ground"at; the third lowerjarniatnreand bacli contacts ofrelay 309. Thiscircuit w-ill cause relay 307' to'flilly operate to close a mmiber ofcircuits forv the purpose'as will hereinafter be described; "Due to theand'lower inner arIn-atnre an'd frontgcontaet,

to ground on the sleeve; On the other hand 'evenf though ring conductorconnectionis "opening of the connection toground through the winding ofrelay '3l4 Y for the tip conductor atth upper outer. armature and backcon-V opened at'the' second lower armatlire an'dback Contact ofrelay307relay-26wi1l remain operated {due to the connections,at-3l7: The

55 rcuit for rel-ay ld ma be traced fflbm 'b at- I tery throughthe'winding'of the rotary mag net 305,'lower outer armature, and backcontact of 1f'elay310 through theconnection 317, lower inner armatureand back contacts of a relay309 overthe ring conductor through theselector S1 and inner upper armature and front contact of relay 201,lower inner armature and back contact of relay 12, lower innerarmaturejand back contact of relay 11, lower inner armature and frontcontact of relay 18, lower inner armature and back contact of relay 14,winding of relay 26 to ground on lead 23. Thefmaintaining of relay 26operated and the release of relay now closes a circuit for the operationof relay 11 from battery, winding of this relay, upper'inner armatureand back contact of relay 25, upper armature and front contact of relay26, upper outer armature and front contact of relay 18 to the ground onlead 23. Relay 11 locks to ground at relay 13, opens the circuit forrelay 10 and extends the connection from the calling subscribers linetobattery and ground through windings of relay 40. ,Relay 40 operates toclose an obvious circuit for relay 14 which closes aholdingcircuit forrelay 13 to mainconnector C. On theoperation of relay 307 p and releaseof relay 314 a circuit was completed from battery through the usualcutoff relay not shown) of line 300 through the sleeve conductor,upperwinding of relay 310 second lower armature and back contact of relay309, third lower armature and front contact of relay 307, second lowerarmature and back contact of relay 310, lower outer ara mature and backcontact of relay 314, third lower armature'and back contact of relay 309to ground, Relay 310 operates in this circuit and locks itself frombattery through .its lower windingand lower inner armature and front,contact, fourth lower armature and front contacts ofrelay'307to'groundindendent of the energizing circuit as estabshed throughcontacts ,of relay 304. Relay 307 when operated also closed anobviouscircuit for the operation of relay 309. Relay 309 was however slow inoperating to permit the momentary, conditions to be established inregard to relay 310 and relays 25 and 26, name y the operation of relay310 andthe momentary release of relay 25 to select the code signal Whenrelay 309 operated it opened the tip and ring connections to the relay314 androtary magnet 305 and when relay 310 operatedthese conductorswere extendedto the called subscribers line'300. As

. r the circuits are now prepared to send the seline'it willbetransmitted as follows. Relay 11 inoperating closes 'a'connection forthe ring conductor from the one ring source connected at the box 32 overlead 33, upper inner armature and back contact of relay 24,

lower winding of ringing trip relay 35'and its lower inner armature andfront contact lower inner armature and front contact of relay 11, lowerinner armature and back contact of relay 12 to the tip conductor throughselector S1,lower inner armature and front contact of relay 309,1ipperinner armature and front contact of relay 310, rin conductor of relay301 due to bells of the su cribers stat-ion connected as shown at 300.These bells being responsive to the one code si a1, it being understoodthat the subscriber aving assignedto'him the one codesignal will onlyanswer thiscall.

When the called, subscriber answers this call by removing the receiverfrom the switchhook a circuit is'completed for the operation of theringing trip relay 35. The return ground connection is completed throughthelsubscribers loopback over the tip conductor as hereinbeforedescribed to the third upper armature and front contact of relay 11 toground at the upper outer armature and back contact of relay 35. Relay35 in operating provides a locking circuit for itself from batterythrough its upper Winding and upper inner armature, and front contact toground at the inner lower armature and front contacts of relay 13. Relay35 in operating opens the ringing circuit at its lower inner armatureandback contact and connects the tip and ring conductors through to thecalled subscriber s line. The connection now extendsfor the tipconductor from the called subscribers line through the third upperarmatureand front contact of relay 35 u p er winding of relay 42 toground and for t e ring conductor from the called subscribers linethrough the lower inner armature and front contact of relay 35 lowerwinding of relay 42 to battery. This provides talking current for thecalled 'subscribe'rs line while talking currentfor thecalling'subscriberris supplied from battery and round through thewindings of relay 40. The connection is now ready for conversation. Whenthe conversation is ended andthe calling subscriber replaces hisreceiver on the hook relay releases, causing the release ofrela'y 14which in turn releases relay 13. Relay 13 causes the release of relays35 and 11. The release of relay 13 closes a circuit fori the operationof release magnet 44 from battery winding: of this magnet, vertical olf--normal 'contacts 45,second lower armature and back contacts of relay12, inner lower armature and back contacts of relay 13. Thisreturnstheselector. S to normal, and the releasecirouit is opened vwhenthe vertical ofinorinal contacts 45 are opened. The release relay .2011This relay vi closes an: ob

or selector S reinoves granite -=rr0n1 thesleeye of'the selector s iouseir- 'cuit for the release magnet 205 which returns selector S1 tonormal, and the circuit for the release magnet is then opened thevertical 'oif-normai 'cor tactf206. Theremoval of the ground from thesleeve of comieetorG, when selector SI returns to horlnal opens theloclr-- ing circuit for 'relay 30? which return frefleasesreiays 309 310and clesesfthe circuit for the release magnet 812tl1rough Verti-*caliorr-norm'al contacts 325, outer lower-e19 mature bacl; contacts ofrelay{307,- third lower armature and back contacts'of relay 309toground' When the connector Chas retu'rnedto hormel, the cirouit' forrelease magnet 312 is opened at umwemmr oat-normal conduetor 325." r l vIf aeonnector in egroup Wired in er-coordance with Fig. 4 assh0Wir'at3l8had beeriselee-ted; thetwo rin'g' code would have beentransmitted to'the called subsc -ibers line 300.

"In this case when'lthegrotary magnet has tinn1shed its function. ofplac ng the brushes of the connector onthe desired l ne and relay 3'14hadoperate'd to ceuse relay 80? to operate, the circuit for irelay' 26would have opened While'the circuit for relay '25 would have been inaintsined due to the connection as shownjat 318. The release of relayQGand the maintaining of reley xoperated closes a circuit forreley 2%from .hatteryrrinding of this relay," upper outer armature and frontcontact of relay upper outer armature and beck contact of relay26,"upp'er outer armatureand front contact o'f'relay-18to ground pick-uple on lead 23. Relay 24 inoperating closes a circuitfo'r the operationof relay 11 from bettery winding of relay 11 and its upper inner mekebefor'e-brealr contacts, upper outer "ar mature and from contact{ ofrelay 24 to ground through the pick-up lead i? to ground atbox 32,51 Thearrangement otthe circuits-for producing theone ring code signal'oiilead 33,;theground onthe pick-up lead t? andtheFtWO ring codesignal onlee'd 48 may :he of any 7 type suitable for this purpose. For exemple theleads33 and 48 may be connected to ringingbattery through interruptersifor producing the desired codes of lay 11 it also connects lead lSWhic-hsupplies the twormgrode throiigh the upper inner armature and frontContact to "the lower winding of relay 35 over the rihg conductorcircuit to thecalled subseribefs line as hereinbefore described. Whenthe ea-lledsubwhich causes the release of this series'oit impulses,relay 514 s scriber answers this 'code relay 35 Qpe'rate's and thetalking'connectionis completed from the called suhscribers line e ah jnbf described.

Ifacenuection is desired to a f-truiik lead f .lngto a distantoiiice,}the connection lS ill'a-tle through line finder LF; selector S,selector S1 and-the connector OlinfFigLfi. The operationot the connectorshown in Fig. 5is similar .to the connecto'r shown in Figi-id exceptthat it is arranged 'to qhuntpver' a group of trunksfor an idleeutoing'trrmk. Th s connector will 'be directively actuated i to selectacertain group of trunks,the brushes thereof will he associatedfwith theterminals of the first brush inthisfgroup. When the connector is seizedby the second selector-S1 ground on the" sleeve causes the partial 'opera'tion of relay 507 to open the circuit'for the release magnetBlQ,Ground on the sleeve also causes relay 510 to be pa rtially operatedover contac ts' 5l3 and close a connection tor the vertical magnet 504,through its third lower armature arid back Contact 'tothe' conductor.The connection to ground-for the tip'oonductor extendstrom the tipto'the upper armature andback contact of rel'ay 509, upper outerarniature and back contact of relay 507, armature and-back contact o'trotary magnet 505, armature a'11cl"ha'ck con' tactor vertical ina-gneti, vei't icel oif' fior mal contacts 503 to ground Thefirstiintical-"direction operates ina griet 5'0, opens thelocki'ng circuitforjtl'leqelay 1"6 inythe pulse for 'actuatingth'e connector in a- Ve'rselector S at the armature andxback'conta ct of magnet 504 and transfersthe ground con nection by; the operation of verti'c al bfiqIOr inalcontacts 503 to ground throu'glrthe Wind- 111g. of relay 514 which ismarginal end does ing of relay 16, so that the succeedihgiinpulsesoperating the vertical 'inagnet' 504: will merely open thelockingcircuit for relay 16; At theen'd of the series of impulses-relay.5105 not operate in series'with the upper-'Wind 51 operates over: thecircuit completed due to, the release of relay 1& as herein'betore de- Iscribed. Relay filatinoperating opens the locking circuit forrelay 510,at its lower outer armature and back contactwvhichthereby releases andprepares the connector iforthe reception of impulses to advance it'intlie rotary direction. The'circuitfor the rotary magnet 505 may no'wbe traced froinbattery,

windiiig of this magnet upper armatu'i'ean'd 'baclrfcontajct orreley526, third lo,We1-' ar 1nature and back contact of relay510,1owe'r- 1nner rmature and back coi'itact of relay'509 to the ringconductor. O'n'the first operation of p the rotary magnet 505 Inresponse 'tothe lasti the lockii'ig circuit for-relay l6i's'ope'11eddigit at the armature and back contactef this magnet and relay 514 isreleased. At-the'end of again opemceem elosee eueuit fertile-1111operation of relay 507 from battery, lower winding of this relay, rotaryoff-normal contacts 520, lower armature and back contact of relay 527,lower outer armature and front contact of relay 514-to ground at thethird lower armature and back contact of relay 509. Re lay 507 inoperating closes a locking circuit for itself to ground on the sleevelead through its lower winding and lower inner armature and frontcontact. I :If the first trunk on which the brushes of connector C1 havebeen placed are busy, ground will be connected to the sleeve terminal ofthistrunk to cause the operation of relay 527 before relay 514 isoperated as follows: Battery, winding of relay 527, fourth lowerarmature and back contact of relay 514, lower make-before-break contactof relay 510, second upper armature and back contact of relay 528 toground on the sleeve terminal of this busy trunk. Relay 527 closes alocking circuit for itself through the lower outer armature and backcontact ofrelay 510, upper inner armature and part contact of relay 52'.lower make-before-break contacts of relay 528 to ground on the sleeve.Relay 514 will now operate as hereinbefore described and cause theoperation'of relay 526 over a circuit from battery through the upperwinding of this relay third lower armature and front contact of relay514, second upper armature and front contact of relay'527, inner lowerarma ture and back contact of relay 528, second lower armature and frontcontact of relay 514 to ground on thefourth or hunting terminal of thebusy trunk. The hunting terminals of all the trunks in the group exceptthe last are connected to ground. The operation of relay 526 closes anobvious circuit for the operation of rotary magnet 505 which opens thelocking circuit for relay 526 extending from battery through thelowerwinding of this relay, lower armature and front contact .of magnet 505,armature and back contact of magnet 504, vertical off-normal contacts503, winding of relay 514 to ground and also the circuit for relay 514.The release of relay 514 causes the release of relay 526 and relay 527will release as the lockingcircuit therefore is opened at the sleevebrush. If the next trunk is busy, the operations hereinbefore describedwill be repeated until an idle trunk is found. When the idle trunk hasbeen found relay 514 operates. Relay 507 will now be fully operated overa circuit from battery, lower winding of this relay, rotary ofi-normalcontacts 520, lower armature and back contact of relay 527, lowerarmature and front contact of relay 514, to ground, at the third, lowerarmature and back contact of relay 509. Relay 507 locks through itslower inner armature and front contact to ground conductor, second upperarmature and back contact of relay 528, make-before-break contacts ofrelay 510, upper outer armature and back contact of relay 527, upperarmature and front contact of relay 514, upper winding of relay 510,second lower armature and back contact of relay 509, inner lowerarmature and front contact of relay 514, second lower armature and backcontact of relay 510, third lower armature and front contact of relaywith the terminals of the last trunk find that there is no groundconnection on the hunting terminal of this trunk and relay 526 willtherefore not be operated after the o eration of relay 527 over thecircuit hereinbefore traced, but relay 528 will instead be operated overa circuit from battery, upper winding of relay 526, third lower armatureand front contact of relay 514, second upper armature and front contactof relay 527, winding of relay 528, make-before-break contacts of relay528 and the second upper armature and back contact of relay 528 toground on the sleeve of the'last trunk. Relay 526 does not operate inthis circuit due to its marginal characteristics. Relay 507 now operateson the operation of relay 528 over a circuit from battery, lower windingof relay 507, rotary off-normal contacts 520, lower outer armature andfront contact of relay 528, lower outer armature and front contact ofrelay 514,-to ground at the third lower armature and back contact ofrelay 509; Relay 509 now operates but relay 510 does not operate due tothe operation of relay 527. A busy tone will now be supplied from thesource 530 and ground at 531 through the second and third upperarmatures and front contacts of relay 507, the two upper outer armaturesand front contacts of relay 528, upper and inner lower armatures andfront contacts of relay 509 to the tip and ring conductors, back to thesubscribers line. The connector will be released on the release of theconnection by the calling subscriber. This release will be accomplishedby removing ground from the sleeve conductorto release relays 528. 527

and 507, relay 507 releasing relay 509. Relay 514 was released on theoperation of relay 507. The circuitfor the release magnet 512 will beclosed on the release of relay 507 through vertical off-normal contacts525, outer lower armature and back contact of relay 507, to

subscribers line at thedistant exchange in the same manner as selectionsare made over selector S1 and connector C. On the first operation ofrelay 652, relay 654 operates over 610, upper inner armature and backcontact of relay 656, upper outer make-before-break contacts of relay611, tip conductor of trunk T1, upper armature and back contact of relay655. second outer right-hand armature and front contact of relay 652 toground through the left-hand winding of relay 4. Relays 654 and610operate in these circuits. The operation of relay 652 opens the circuitfor relay 655 which was closed to ground at the outer left-hand armatureand front contact of relay 650 to prevent relay 655 from operating atthis time. On the release of relay 652, relays 654 and 610 release butdue to the slow to operate characteristic of relay 655 and releaseof'relay 652, relay 655 is prevented from operating during the pulsingof relay 652. I 1

Relay 610 now follows the impulses controlled by relay 652 to advancethe selector S2 in the vertical direction. The operation of relay 610closes an obvious circuit for relay 618 which relay remains operatedduring the pulsing. Relay 610 also in operating discharges the condenser615 and on the first release of relay 610, relay 616 is operated over anobvious circuit through its upper winding due to the charging ofcondenser 615. Relay 616 in operating closes a circuit for verticalmagnet 637 from battery, winding of this magnet, lower inner armatureand back contact of relay 618, upper armature and front contact of relay616, conductor 623, fourth upper armature and back contact of relay 611.lower outer armature and back contact of relay 624 to ground at thearmature and front contact of relay 613. Relay 616provides a lockingcircuit for itself from battery through'its lower winding, and lowerinner armature and front contact, upper outer armature and back contactof relay 618, ro-

" tary ofi-normal contacts 620, vertical off-norfor relay 616 at thesecontacts to the upper.

winding of relay 628 and ground at the armature and backcontact ofvertical magnet 627 so that on the succeeding impulses the release ofrelay 616 is under control of the vertical magnet. The operation ofrelay 1 16 characteristics.

also closes an obvious circuit for the operation of relay 614 whichremains operated during the pulsing due to its slow release On theoperation of relay 614 a circuit is completed for the operation ofrelays 625' and 626 as follows: Battery, winding of relay 625, innerlower armature and front contact of relay 614, winding of relay 625 toground on lead 623.

At the end of the pulsing for this digit on the release of relay 616,relay 614 releases and closes a circuit for the operation of relay 628in series with relay 625 from battery, winding of relay 625. outer lowerarmature and back contact of relay 614, lower inner at mature and backcontact of relay 616, upper inner armature and back cont-act of relay618, rotary olf-normal contacts 620, vertical olfnormal contacts 621,upper winding of relay 628 toground at the armature and back contact ofmagnet 627. Relay 626 is also maintained operated while relay 614 isreleased over a circuit from battery, winding of magnet 627, lower innerarmature and back contact of relay 618, lower inner armature and backcontact of relay 614, winding of relay 626 to ground on lead 623.

The. operation of relay 628 closes an obvious circuit for the operationof rotary magnet 630 forthe purpose'of advancing the brushesof's'elector S2 in. a rotary direction. The operation of the rotarymagnet shifts the rotary off-normal contact 620 to open the circuit forrelay 628 so that this relay will now release and cause the release ofrotary 'magnet 630. If the first trunk and the associated secondselector to which the brushes of selector S2 have established aconnection is busy there will be a ground on the sleeve conductor ofthis trunk which causes the reoperation of relay 628 over a circuit frombattery, lower winding of relay 628, the armature and back contact ofrotary magnet 630, rotary off-normal contacts 631, lower outer armatureand back contact of relay 618, lower outer make-before-break contacts ofrelay 611, armature and back contact of relay 658 to the ground on thesleeve. Relay 628 in operating closes the circuit for magnet 630 whichopens the locking circuit for relay 628. This alternate operation ofrelay 628 and magnet 630 will continue until an idle trunk is found whenrelay 618 willop erate, over a circuit from battery, lower winding ofrelay 628, armature and back contact of magnet 630, rotary off-normalcontacts 631, winding of relay 618 to ground on lead 623. Relay 628 ismarginal in character and will not operate in series with relay 618.Relay 618 in operating shifts the pulsing circuit to the ring conductorof the selected trunk from ground on lead 623 and the upper armature andfront contact of relay 616,,to lower inner armature and front Contact ofrelay 618, lower inner armature means responsive to the 0 eration andrelease of said pulsing relay r actuating said help relay, a holdingrelay in the first switch, means for operating said holding relay inresponse to the operation of said pulsing relay, a changeover relay insaid first switch, means for operating said changeover relay in responseto the operation of the help relay,

means for locking said holding relay in operated condition under controlof said changeover relay, means for locking said help relay undercontrol of said holding relay, and

means for transferring said locking of the help relay from the holdingrelay to the operating magnet of the first switch and to the operatingmagnets of the succeeding switch as they are added in the train.

6. In a telephone system, two switches, a

. pulsing relay in the first switch, operating magnets for said switchesfor actuating them to establish a connection between them, a help relayin the first switch, means for actuating said help relay in response tothe actuation and release of the pulsing relay, a

F so

changeover relay, means for actuating said changeover in response to theactuation of the help relay, a locking circuit for said help relaycontrolled by the operating magnet of the first switch, a locking switchfor said help relay controlled by the operating magnet of the secondswitch, means for transferring the help relay from control by the firstlocking circuit to control by a second locking circuit in response tothe establishing of a connection between. the first and the secondswitch,

. a' changeover relay in the second switch included in the secondlocking circuit but unresponsive in said locking circuit, means forestablishing a no resistance path for said second circult in response tothe release of the changeover relay in the first switch for the betweensaid switches and the release of said help and changeover relaysin thefirst switch for actuating the changeover relay in the second switch.

8. In a telephone system, a train of switches, a pulsing relay in thefirst switch,

operating magnets in all of said switches for actuating said switches insuccession to complete a connection through said train of switches, ahelp relay in the first switch, a changeover relay in each of saidswitches, means for'operating the help relay in response to theoperation and release of the pulsing relay, means for holding said helprelay operated under control of the operating magnets in the succeedingswitches as they are added to the train, means for actuating thechangeover relay in response to the actuation of the help rela while aseries of impulses are transmitted y the pulsing relay, and meansresponsive to the release of the help relay and the changeover relay inthe first switch for actuating the changeover relays in the succeedingswitches when the switches are added to the connection.

9. In a telephone system, a first relay, 9, second relay, means foractuating the first relay, means for actuating the second relay inresponse to the actuation of the first relay,

a third relay having marginal characteristics, a circuit for said thirdrelay including a high resistance winding of the first relay when saidfirst relay is energized to maintain said third relay in a non-operatedcondition and a circuit completed through a low resistance path andresponsive to the release of the first relay foractuating said thirdrelay.

10. In a telephone system, calling lines, party lines, groups of finalswitches having access to said party lines, preceding switches forconnecting calling lines with party lines through final switches, codesignaling means associated with preceding switches for signaling partylines, two relays in a preoed ing switch for controlling the connectionof the code signal to be transmitted, means responsive to theestablishing of a connection through final switches of one group forcontrolling said relays to select one code and through the finalswitches of another group for controlling said relay to select anothercode, and means responsive to the establishing of connection to a partyline for transmitting the selected code.

11. In a telephone s stem, calling lines, partylines, groups of nalswitches having access to said party lines, preceding switches forconnecting calling lines with party lines through final switches, codesignaling means associated with preceding switches for signaling partylines, two relays in a preceding switch for controlling the connectionof the code signal to be transmitted, means responsive to theestablishing of a connection through final switches of one group forreleasing one relay and maintaining the other operated to select onecode and through the final switches of another group for releasing onerelay and maintaining the other relay in the reverse order to selectanother code and means responsive to the establishing of connection to aparty line for transmitting the selected code.

12. In a telephone system, calling lines, party lines, groups of finalswitches having access to said party lines, preceding switches forconnecting calling lines with party lines through final switches, codesignaling means associated wit-h preceding switches for sigline and thetrunk with the battery feed supply included." f i 20. In a telephonesystem, calling lines, called lines, trains of switches for connecting acallin line with a called line, two relays in a prece ing switch, meansfor maintaining said relays operated during the establishing of aconnection, a third relay in said preceding switch, means for actuatingsaid third relay in response to the establishing of a conj nection to acalled line, a signaling means in said preceding switch, and meansresponsive to the actuation of all three relays for dis abling thesignaling means.

21-. In a telephone system, calling lines, called lines, trains ofswitches for connecting a calling line with a called line, two relays ina preceding switch, means for maintaining said relays operated duringthe establishing of a connection, a third relay in said precedin switch,means for actuating said third re ay in response to the establishing ofa connection to a called line, a signaling means in said recedingswitch, a battery feed supply in said preceding switch for the callingline and the called line, and means responsive to the actuation of allthree relays for disabling the signaling means and for preventing saidbattery feed supply from being included in the connection.

22. In a telephone system, calling lines, jcalled lines, trains ofswitches for connecting a calling line with a called line, signalingmeans in a preceding switch, a battery feed supply in saidprecedingswitch for the calling hue and the called line, and means in saidpreceding switch responsive to the establishing of a connection to thecalled line for disabling said signaling means and for preventingbatteryfeed from being included m the connection.

23. In a telephone system, calling lines, called lines, trains ofswitches for connecting a callin line with a called line, two relays ina prece' in switch, means including battery and groun connections forthe tip and ring conductors for maintaining said relays operated duringthe establishing of the connection, a third relay in said precedingswitch,

means for adding a booster battery to the tip conductor of saidconnection in response to the establishing thereof to a called line forated during the establishing of the connection, a third relay in saidpreceding switch, means for addinga booster battery to the tip conductorof said connection in response to the establishin thereof to a calledline for actuating sai means in said preceding switch, a battery feedsupply in said preceding switch for the calling line and for the calledline, and means responsive to the actuationof all three relays fordisabling the signaling means and for peventing said battery feed supplyfrom ing included in said connection.

25. In a telephone system, calling lines, called lines, a train ofswitches for connecting a calling line with the called line, two re aysin the receding switch, a third relay in said preceding switch, acircuit including one of said first mentioned two relays and a thirdrelay in series in the tip conductor, a circuit including the other ofsaid first mentioned two relays in the ring conductor, means including abattery connected in the circuit for the tip conductor to maintainoperated the relay in said circuit of the first mentioned tworelays andfor maintaining a third relay in said circuit released and a groundcon-,

nection in the circuit for the ring conductor for maintaining the relayincluded therein operated, means for adding booster battery to thecircuit for the tip conductor in response to the establishing of aconnection to the called line for actuating the third relay in thiscircuit, a signaling means in the preceding switch, and means responsiveto the actua tion of all three relays for disabling said signalingmeans. 7

26. In a telephone system, calling lines, called lines, a train ofswitches for connecting a calling line with the called line, two relaysin a preceding switch, a third relay in said preceding switch, a circuitincluding one of said first mentioned two relays and a third relay inseries in the tip conductor, a circuit including the other of said firstmentioned two relays in the ring conductor, means including a batteryconnected in the circuit for the tip conductor to maintain operated therelay in said circuit of the first mentioned two relays and formaintaining a third relay in said circuit released and a groundconnection in the circuit for the ring conductor for maintaining therelay included therein operated, means for adding booster battery to thecircuit for the tip conductor in response to the establishing of aconnection to the called line for actuating the third relay in thiscircuit, a signaling means in the preceding switch, a battery feedsupply in said preceding switch for the calling line and for the calledline, and means responsive to the actuation of all three relays fordisabling the signaling means and for preventing said battery feedsupply from being included in said connection.

In witness whereof, I hereunto subscribe my name this 25th day of July,1930.

' RALPH L. QUASS.

called relay. a signaling

